Automatic transmission



Feb. 18, 1936. c. F. RAUEN ET AL AUTOMATIC TRANSMISSION Filed Aug. 5,1953 5 Sheets-Sheet l 1NVENTOR5. Carl 7. Fave,

flno Z. H'lpela.

ATTORNEY.

Feb. 18, 1936. c RAUEN ETAL I I 2,031,067

AUTOMATIC TRANSMIS S ION Filed Aug. 5, 1933 5 Sheets-Sheet 2 x lINVENTORS. 1 Carl F Fqrerz R H270 Z. ffzlpel z. 3 BY M N w N m g ILlllllllllll l l ATTORN Y.

Feb. 18, 1936. c. F. RAUEN EML I 2,031,067

AUTOMATIC TRANSMISSION Filed Aug. 3, 19 53 5 Sheets-Sheet 3 INVENTORS.Carl E Fallen. Have 2?. z'lpela,

BY Mm ATTORNE Feb. 18, 1936.

c. F. RAUEN ET AL AUTOMATIC TRANSMISSION Filed Aug. 5, 1933 5Sheets-Sheet 4 ,5 o 5% 2 W" r Feb. 18, 1936.- RA ET AL 2,031,067

- AUTOMATIC TRANSMIS S ION Filed Aug. 5, 1953 5 Sheets-Sheet 5 Zpeh 1 myORNEY ATT Patented Feb. 18, 1936 V UNITED ',ISTATES1 PATENT OFFICEAUTOMATIC TRAN SMISSION Carl F. Rauen, Grosse Pointe, and Ano E.Kilpela,

Detroit, Ml

b., assignors, by mesne assignments, to Borg-Warner Corporation, acorporation of Illinois Application August 3, 1933, Serial No. 683,449

11 Claims.

automatic change speed mechanism for operatively connecting a drivenshaft withv a driving shaft in a plurality of different gear ratios,automatically operable mechanism for changing from an intermediate gearratio to a high gear ratio or from a high gear ratio to an intermediategear ratio, and means operable at any time after a predetermined speedof the driven shaft has been attained for controlling the operation ofthe gear changing mechanism.

An object of the invention, therefore, is to provide a transmission inwhich the change from an intermediate .gear ratio to a high gear ratioor vice versa, may be automatically effected, at any time after apredetermined speed of rotation of the driven shaft has been attained,in accordance with the volition of the operator.

Another object of the invention is to provide a transmission in whichthe change from an intermediate gear ratio to a high gear ratio will beautomatically effected at any time after a predetermined or criticalspeed of rotation of the driven shaft has been attained, uponsynchronization or approximate synchronization of the speed of rotationof the driving shaft with that of the driven shaft.

Another object of the invention is to provide an automatic transmissionadaptable for varying the driving connection ratio between the drivingshaft and the driven shaft from an intermediate gear ratio to a highgear ratio or from a high gear ratio to an intermediate gear ratio undera plurality of predetermined conditions optionally selectable by theoperator of the vehicle.

Another object of the invention is to provide a means whereby theautomatic gear changing mechanism may be locked out so that a manualselective shift may be made by the operator of the vehicle, fromautomatic high gear ratio to a selective intermediate gear ratio, orfrom an automatic intermediate gear ratio to a selective high gear ratioat any time without regard to the speed of the engine, orof the vehicle,without the necessity of declutching, and without manually opposing theaction of theautomatic gear changing mechanism.

Another object of the invention is to provide, in connection with anautomatic transmission, means for synchronizing the speed of the drivingshaft with that of the driven shaft, or reducing the relative difierencebetween the speeds of ro tation of said shafts, so that the automaticchangefrom one gear ratio to another gear ratio may be effected withoutdisconnecting the engine clutch.

Another object is to provide an automatic transmission in which all ofthe gear changes can be accomplished only while the gears to be meshedare synchronized so that any shock or clashing of gears is eliminated.

Another object of the invention is to provide an automatic transmissionin which a change tation of the driven shaft attains a predetermined orcritical rate of speed.

Another object is to provide an automatic transmission which isrelatively simple in design and. construction and which readily lendsitself to commercial production.

Other objects and advantages will appearfrom the following description:

Referring to the drawings, of which there are five sheets,

Fig. 1 is a view showing the installation of our automatic transmissionin an automotive vehicle;

Fig. 2 is a. longitudinal side elevational view partially in section ofa preferred form of our automatic transmission having a front end freewheeling unit';

Fig. 3 is a longitudinal view partly in section showing a differentmethod of incorporating a free wheeling unit in theautomatictransmission illustrated in Fig. 2;

Fig. .4 is a top plan view of the automatic shifting mechanism takengenerally on the line 44 of Fig. 2;

Fig. 5 is avertical transverse sectional view of the mechanism forcontrolling the automatic shifting apparatus taken generally on the line5-5 of Fig. 2 and looking in the direction of the arrows;

Fig. 6 is a vertical cross sectional view taken on the line 6-6 of Fig.2 and showing parts of the jaw clutch and yoke rods in detail;

Fig. 7 is an enlarged view taken on the line of Fig. 2 and showingdetails of the jaw clutch mechanism;

Fig. 8 is a diagrammatic view of the gear shift positions for theautomatic transmission illustrated in the preceding figures and as seenfrom the position of the operator of the vehicle;

Fig. 9 is a side elevational view partly broken away illustrating amodification of the mechanism for controlling the automatic shiftingapparatus;

Fig. 10 is a top plan view on the line of Fig. 9 and showing thecontrolling mechanism and shifting apparatus;

Fig. 11 is a cross sectional view taken on the line of Fig. 10 andillustrating the details of the controlling mechanism;

Fig. 12 is a cross sectional view taken on the line |2--| 2 of Fig. 11showing details of the vacuum valve controlling governor;-

Fig. 13 is a view illustrating a modification of our invention andshowing a two forward speed transmission using a jaw tooth clutch whichis adapted to effect an automatic shift from low to free wheeling high,or vice versa;

Fig. 14 is a top plan view taken generally on the line I l-I4 of Fig. 13and showing the controlling mechanism and shifting apparatus for thetransmission illustrated in Fig. 13;

Fig. 15 is a side elevational view partly in section illustrating amodification of our invention and showing a different type of clutchwhich is adapted to effect an automatic shift between low and high gear;and

Fig. 16 is a diagrammatic view of the gear shift positions for theautomatic transmission illustrated in Fig. 13 and as seen from theposition of the operator of the vehicle.

Referring to Figs. 1, 2 and 4 of the drawings,

ing from the housing 6 is a portion of the main or drive shaft I.

A housing 8 mounted upon the cover of the transmission 4 is internallyprovided with a shoulder 9 providing a bearing I for an annular enlargedportion |2 of a gear shift lever l3. A knob I4, formed on thebottom endof the gear shift lever, is adapted for engagement with the gatescarried by the yoke rods. A plurality of slots 15 are provided at theupper end of the housing 8 in the shoulder 9 for receiving trunnions |6projecting from the annular enlarged portion l2 of the gear shift lever.A capl'l is threadedly secured to the upper end of the gear shift leverhousing 8. Disposed around the" gear shift lever and between the cap l1and the annular enlarged portion |2 of the gear shift lever is a coilspring l8 for resiliently holding the gear shift lever in a verticalposition.

The transmission case is provided with two internal transverse wallswhich divide the tran-' mission case into a forward free wheelingcompartment, a main gear compartment and a compartment for housing themechanism controlling the shifting apparatus. The forward wall 20 of thetransmission case provides a support for the driving shaft bearing 24which is secured in the aperture 26 by retaining rings 25. A drivingshaft 21 is connected to the engine l of the automotive vehicle througha clutch 2, and is counterbored at 29 to receive the forwardlyprojecting end of an intermediate shaft 3|. Intermediate shaft 3| isjournaled in a bearing 321, suitably secured in an aperture in the wall2|, such as bya retaining washer 34 held in .place by a snap ring 35.

, shaft.

A hub 31 is splined to the driving shaft 21 adjacent the end thereof andis provided with radial gear teeth 38 and an annular groove 40. Adriving member 42 of an overrunning clutch, in:- dicated generally at 43and of well known construction, is splined to one end of the drivingshaft 21 and is provided about the periphery thereof with a series ofcammed surfaces and for each of which there is provided one of a seriesof rollers 45 which are adapted to engage the inner surface of a drivenmember or shell 46 for providing a one-way drive between the' drivingand driven members. A thrust washer 49 is disposed between the end ofthe driving member 42 and a shoulder 48 on the shell 46. A washer heldin place by a snap ring 52 serves to retain the rollers 45 in positionbetween the driving and driven members of the overrunning clutch. Theshell 46 is splined to the intermedi ate shaft 3|, forward of thebearing 32, and is held in place by a snap ring 33.

The operation of the overrunning clutch is such that the driving shaft21 will drive the intermediate shaft 3| through the driving member 42,rollers 45 and driven member or shell 46, but will permit theintermediate shaft 3| to overrun, or rotate at a speed greater than thatof the driving shaft 21.

Disposed about the inside of the shell 46 adjacent its outer end are aset of teeth 53 which are adapted under certain conditions to mesh withthe teeth 38 on the hub 31. A Bowden wire control (not shown) may bepositioned on the dash board in the drivers compartment of the.automotive vehicle to operate a shifting fork (also not shown) which isadapted to be received in the groove 40 for the purpose of shifting thehub to mesh the teeth 38 with teeth 53, thereby locking the intermediateshaft 3| to the driving shaft 21 and locking out the overrunning clutchmechanism. This may be desirable under certain drive ing conditions inorder to keep the vehicle under a greater degree of control. When theoverrunning clutch 43 is locked out, free wheeling is eliminated in allspeeds.

The extreme forward end of the intermediate shaft 3| is journaled in abushing 55 in the innermost end of the counterbore 29 in the driving Thedriven shaft 1 is counterbored at its forward end to receive a reducedportion 6| of the intermediate shaft 3| and is provided with a rollerbearing 63 for supporting the same. The driven shaft 1 is journaled atits forward end in a bearing 65 mounted in an aperture in wall 22 of thetransmission casing 5. The bearing is retained therein by a plate 66suitably secured to the wall 22 of the transmission casing, such as byboltsv 61 and by a snap ring 68. A similar bearing is secured in thehousing 6 carried by .the rear wall 23 of the transmission casing forsupporting the rear end of the driven shaft 1. The housing carried bythe rear wall 23 of the transmission casing provides an enclosure forthe speedometer gear 1 I, worm i2 and shaft 13. Gear II is mounted upona coupling member 14 which is fixedly mounted upon the driven shaft 1.

A countershaft I5 is journaled in walls 2| and 22 of the transmissioncasing and is locked against rotation byjbolt 16 which is threadedlysecured in the bottom of the, casing 4 and engages an aperture 11 in thecountershaft 15. The countershaft 15 carries freely rotatable thereon asa unit, a cluster of gears comprising a pair of helical gears 18 and I9and pinion gears 8|) and 8|. Suitably formed on the intermediate shaft3| is :helical gear 18 on countershaft 15. A second helical gear 83 iscarried on a bushing 85 freely mounted on the shaft 3| and is adapted tomesh with gear 19 on the countershaft. A thrust washer 86 is disposed onthe intermediate shaft 3| between gears 82 and 83. An annular ring 88providing a thrust member for the helical gear 83, is keyed to theintermediate shaft 3| by pin 98' and is maintained in position adjacentthe gear 83 by a snap ring 9|. Gear 83,-which is in constant mesh withgear 19, is provided with a series of jaw teeth 92 on one face thereof.

Referring to Fig. '7, which illustrates the details of the jaw clutchmechanism, it may be seen that the gear 83 is provided .with a set offour jaw teeth 92 disposed around one face thereof, which are providedwith cammed or pitched surfaces or faces 93. A jaw clutch member 98carried on a bushing 96 freely mounted on the intermediate shaft 3| isprovided with a set of pitch faced jaw teeth 94 adapted to engage teeth92, but the faces of which teeth are pitched in a direction opposite tothat of the pitched surfaces 93 on the teeth 92.

It is desirable to pitch the jaw teeth 92 and 94 in the mannerillustrated, in order to prevent the driven shaft, to which the clutchmember 98 may be connected, when rotating faster than the driving shaft,or than the gear 83, from picking up the engine through the same with aconsequent breakage of parts, assuming over-.running clutch 43 wasomitted or locked out If the overrunning clutch 43 is used and cannot belocked out, it would be immaterial, as far as the function or operationis concerned, whether the surfaces of the jaw teeth are pitched in adirection opposite to that shown, or are disposed so that the faces ofall of the teeth will lie in two parallel planes, or whether the teethused are stepped, staggered or otherwise formed, so long as intermeshingmembers are provided on the gear 83 and clutch member 98, since theoverrunning clutch 43 would permit the intermediate shaft 3| to overrunthe driving shaft 2 The jaw clutch member 98 is provided on its oppositeface with .a set of jaw teeth 95, pitched similarly to teeth 92 andwhich are adapted under certain conditions to mesh with jaw teeth 91' onclutch member 98 which is splined on the shaft 3| and retained inposition by snap rings j |88. Jaw clutch member 98 is also provided witha series of radial teeth 8|.

The clutch member 98 is provided with a spring pressed poppet 9| whichis adapted to engage in annular grooves 92' or 93 provided in theintermediate shaft 3|.: These grooves are adapted to engage the poppet9| for. the purpose of holding the clutch member 98 in either of itspositions.

until the mechanism for moving the clutch member 98 has built upsufficient force to snap the clutch member from one position to theother. This will insure a positive disengagement of the clutch from onemember and engagement with the other member in a single operation andwill 'eliminate any possibility of having the clutch disengaged from onemember and not immediately engaged with the other member. The

spring pressure of the poppet 9| may be varied to alter the speeds atwhich automatic changes in the driving gear ratio are effected.

As shown in Figs. 2 and 7, the jaw clutch mechanism is in neutralposition. Assuming that the driving shaft 21 is being rotated by theengine, gear 83 and clutch member 98 will rotateat a reduced rate ofspeed with respect to the rate of speed of the driving shaft 21 becausesuch gear is driven through the speed reduction gears I8 and 19 on thecountershaft. Clutch member 98 provided with pitch faced jaw teeth 91and splined to the intermediate shaft, will rotate at the same rate ofspeed as the driving shaft 21, because such member is directly connectedthrough the shaft 3| and overrunning clutch 43 with the driving shaft,but will rotate at a greater rate of speed than gear 83 and clutchmember. 98. The jaw teeth 95 and 91 are provided with pitched surfaces95' and 91 which are oppositely disposed with respect to each other sothat rotation of member 98 at a rate of speed greatly in excess ofclutch member 98=will cause the teeth 9'! to jump the intersticesbetween the teeth 95 on the clutch member 98 whenthe same is moved tothe right for engagement with member 98.

The teeth 95 and 91' will not interlock when the member 98 is rotatingat a. much faster rate of speed than that of the clutch member 98, butwill interlock if the speeds of the members are approximately the same.When the teeth 91 jump the interstices between the teeth 95, a noise iscreated thereby, varying in intensity with the difference in speedsbetween the members 98 and 98. The noise will also vary with the pitchof the surfaces 95' and 91' and with the number of teeth used, the useof a lesser number of teeth permitting a reduction of the pitch of thesur-. faces and the use of a greater number of teeth necessitating anincrease of the pitch of the v surfaces 95' and 91'. Deceleration of thespeed of I rotation of the member 98 until it approximates that ofmember 98, will permit the teeth to drop into the correspondinginterstices on the engaging member. If the jaw clutch member 98 tends torotate faster than member 98 before the teeth engage, theshoulders'formed at the high points of the teeth will engage. A maximumcircumferential travel of less than ninety degrees may be neces-' saryto effect engagement of the shoulders formed at the high points of theteeth and 91, depending upon-the relative positions of such shoulders atthe time when both members are traveling at the same rate of speed.Subsequent relative acceleration of the speed of rotation of the member98, or reversal of drive, such as by an increase 95 and 91 and permitsuch teeth to drop into their corresponding interstices before torque isapplied between the engaging shoulders formed on the low points of theteeth 95 and 91. The jaw teeth 92 and 94 on the gear 83 and clutchmember 98 are adapted to engage in the same manner except that the teethare so disposed that the clutch member 98 is adapted to overrun the gear83 until the speeds thereof are approximately synchronized.Disengagement of the jaw teeth 95 and 91 prior to interlocking of theteeth 94 on clutch: member 98 with teeth 92 on gear 83 will take placeupon release of torque between teeth 95 and 91 incident to closing ofthe en gine throttle l8.

Although we have shown the jaw clutch members provided with a set offour jaw teeth, it

may be desirable under some circumstances to use a different number ofjaw teeth. In determining the desirable: number of teeth to be used orjumping shocks resulting when the driven shaft picks up the drivingshaft and/or engine, should be considered. Use of an overrunning clutch,such as 93, practically eliminates such shocks. The use of a lessernumber of teeth than four would permit a reduction of the pitch of thesurfaces ofv such teeth, thereby decreasing the noise due to theover-ratcheting or jumping of the teeth before interlocking, but wouldincrease the maximum circumferential travel necessary to effectengagement of the jaw teeth with a consequent increase in the shockattending such engagement. An increase in the number of jaw teeth wouldproduce effects just the reverse of that describedthat is, the noisewould be increased due to a greater number of teeth and. a

. teeth I06 which are adapted to mesh with'and slide upon the teeth I04of the clutch member I03. A gear I I is slidably splined on the drivenshaft 1 and is adapted to mesh with gear 80 to provide a low geardriving connection with the. .driving shaft and to mesh with mountedupon a shaft II4, which gear is-in conidler gear I I2 stant mesh withgear 8 I, to provide a reverse gear driving connection between thedriving shaft and the driven shaft.

A sleeve II5 having a pair of grooves H6 and H1 is slidably positionedon the driven shaft 1 and is resiliently held in the position shown inFig. 2 of the drawings. A collar II8 fixed to rotate with the drivenshaft I and secured against lateral displacement by snap rings H9, isprovided with a series of arms I26. A compression spring I2I is disposedabout the driven shaft 1 between the sleeve H5 and the collar II8 forthe purpose of biasing the sleeve to the left. Pivoted to each arm I20is a bell crank lever I22, one end of each of which is adapted to engagein groove H1 and the other end of each of which is weighted as at I23 toprovide a series of centrifugal weights. Groove H6 is adapted to receivea fork I25 carried by the yoke rod I60. A drain plug I26 is provided atthe bottom of the casing 5 for the purpose of draining the oil from thesame.

Slidably positioned above the gearing and secured in the walls of thetransmission casing are a series of yoke rods which serve to carry theshift forks and which are actuated by movement of the gear shift leverI3. Referring particularly to Fig. 4, yoke rod I30 isprovided with aseries of notches I3I, I32 and I33, respectively. These notches areadapted to engage a spring pressed poppet, such as that shown at I34,for the purpose of holding the rod against accidental displacement. Thenotches correspond respectively with the reverse, neutral and lowpositions of the fork I36 carried by the rod I36.

Secured upon the yoke rod I30 by a bolt I31 is a collar I3 5 whichcarries a shifting fork I36 which is adapted to engage a groove I38 onthe gear IIO for the purposeof moving the same to the left intoengagement with the gear 80 for placing the driven shaft 1 in low gearratio with respect to the driving shaft, and to move the gear to theright into engagement with idler gear I I2 for the purpose of placingthe driven shaft I in reverse ratio with respect to the driving shaft21. To accomplish this, the operator of the vehicle moves the handle ofthe gear shift lever to the left, (looking at Fig. 8), whereupon theknob I4 at the bottom end of the gear shift lever I3 will engage a gateI40 carried by a collar 142 which latter is secured by a bolt I43 uponthe yoke rod I30.

If the operator of the vehicle moves the han dle of the gear shift leverto the upper left hand corner, as shown in Fig. 8, the knob of the gearshift lever will engage the gate I40 and move the same to the right,(looking at Fig. 4), thereby bringing notch I3I into engagement with thepoppet, so that the transmission will now be in reverse gear. to bringthe handle of the same to the lower left hand corner, (looking at Fig.8), the yoke rod I30 will be moved to the left, (looking at Fig. 4) tothe position where the notch I33 will engage the poppet. In thisposition the gear IIO will engage the gear 80, having been moved intothat position'by the fork I36, and the transmission will be in low gear.

A second yoke rod I45, slidably secured adjacent the yoke rod I30 to thewalls 2| and 22 of the transmission casing is provided with a pair ofnotches I46 and I41 on the under side thereof which are adapted toengage a poppet or detent I34. Midway of the yoke rod I45 is a collarI50, fixedly secured as by a bolt I52 to the yoke rod, which carries ashift fork I53 adapted to engage in a groove I54 in the internallytoothed sleeve I05 for the purpose of shifting the same to the left,looking at Fig. 2, so that the teeth I06 thereof will engage with theteeth IOI on clutch member 90. A gate I55 adapted to receive the knob I4at the bottom end of the gear shift'lever is secured by a bolt I56 tothe yoke rod I45 so that the knob I4 may be moved into engagementtherewith, as shown in Fig. 4, and moved into engagement with the gateI40 on yoke rod I30. The yoke rod I45 is used for placing thetransmission into automatic gear ratio, when the notch I41 will engagedetent I34.

A third yoke rod I60 is secured in the upper end of the transmissioncasing in the walls 2I and 22 so as to be capable of sliding movementwith respect thereto. The yoke rod I60 is provided with a pair ofnotches I6I and I62 on the under side thereof, a cutaway portion I63 anda flatted portion I65. A gate I66 is mounted on yoke rod I60 between twocompression springs I61 and I68 so as to be capable of sliding movementwith respect to yoke rod I60. A pin I carried by the yoke rocl I60 holdsthe spring I61 in place against the gate I66. Collar I1I secured by boltI12 .to the yoke rod I60 engages one end of the spring I68 for holdingthe same in place and is provided with a shift fork I which is adaptedto engage with an annular flange I16 on clutch member 90.

Carried on the upper side of the gate I66 is a cylinder I18 which isdisposed transversely to the axis of the yoke rod I60 and which carriesa pin I80 having a rounded head I8I. Disposed between the head I8I ofthe pin I80 and a shoulder I82 in the cylinder I18 is a spring I19 whichtends to hold the head of the pin in position, as shown in Fig. 4. Theyoke rods I30, I45 and I60, as shown in Fig. 4, are in neutral position,and it will be observedthat the mouth of the gate I66 is slightly offsetwith respect to the gates I40 By manipulating the lever so as and I55 sothat it is impossible for the knob of the shift lever to enter the-gateI66 fromva neutral position. T

' Carried by the yoke rod I60 adjacent the flatted portion I65 thereofis a sleeve I 83, having a bolt I85, the end of which engages theflatted'portion I65 of the yoke rod I 60. The sleeve I83 is mounted onthe yoke rod I60 so as to be capable of sliding movement with respectthereto, and carries the fork I25. The sleeve I83 is provided with apair of lateral arms I81, having a pin I88 pivotally supporting a rockerarm I90, which carries a pair of heads I9I and I92. A shaft I94 issecured slidably with respect to the walls 22 and 23 of the casing andis provided with a cutaway portion I95. The shaft I94 is resiliently hedin its right hand position, by a spring I98 which is secured at one endto a pin 200 on the shaft I94 and at the other end to a headed pin 202can'ied by the wall 23. Lug I91 on the shaft I94 limits the movement ofthe spring and shaft I94 in one 1 direction.

Yoke rods I30, I45 and I60 are provided with a set of interlockscomprising a series of notches 205 disposed in the adjacent sides of theyoke rods and a plurality of slidable pins 206 and 201 for engaging saidnotches in such a manner that it is impossible to move more than oneyoke rod at a time. Movement of one of the yoke rods moves one of thepins out of the notch on such yoke rod and into a notch on the adjacentyoke rod.

Referring to Fig. 3 of the drawings, there is shown a modified form ofpart of a trans- 1 mission incorporating a free wheeling unit oroverrunning clutch, similar in design to that previously described, inthat part of the transmission between the intermediate and drivenshafts. In this modification the overrunning clutch is omitted from thefront end of the transmission which will have the eiTect of therebygreatly shortening the length of the transmission casing and enablingthe intermediate shaft to be made integral with the driving shaft 21.

The driving shaft 21 is provided with a series of cammed faces radiallydisposed about its periphery, between which and the inner surface ofclutch member 98 a series of rollers 2I0 are carried. Thrust washers 2I2keyed to the driving shaft by pins 2 I4 and held in'place by snap rings2I6 are provided for holding the rollers 2I0 in place between the clutchmember 98 and the Fig. 3, free wheeling is provided only in high gearand cannot be locked out, whereas in the device illustrated in Fig. 2,free wheeling is op tionally provided in all speeds.

As illustrated in Figs. 2, 4, 5, 6 and '7, the transmission is inneutral gear; that is, there is no driving connection between thedriving shaft 21 and the driven shaft 1. Manipulation of the gear shiftlever I3 into low position-that is, in the lower left .hand position(see Fig. 8), will cause the knob portion of the gear shift lever I3 toengage gate I40 for moving the yoke rod I30 to the left (looking at Fig.4), to a position where the notch I 33 -will engage a detent such asI34, by which the fork I36 will be shifted to the left which will causethe gear II to slide upon the driven shaft 1 to mesh with the gear 80 onthercountershaft 15. The car will now be in low intermediate shaft 3|,gears ing shaft 21, through the overrunning clutch 43, 82, 18, 80 and H0to driven shaft 1. Driving connection for reverse gear will be similarexcept that gear IIO will be in mesh with idler gear II2 which is inconstant mesh with gear 8|. Reverse gear is effected by moving the gearshift lever to the upper left hand corner (looking at Fig. 8), whichwill cause the yoke rod I30 to be shifted until the notch I3I engageswith a detent such as I 34. It will be noted that when the transmissionis in neutral positiomjaw teeth 92 in interlocking engagement with jawteeth 94 on the jaw clutch member 90 and that when the engine isoperating, the clutch member will be rotating on the intermediate shaftand be co nected to the drving shaft through the intermediary ofoverrunning clutch 43, intermediate shaft 3I, gears 82, 18, 19 and 83and interlocking jaw clutch teeth 92 and 94. Manipulation of the gearshift lever into the automatic (second and high) position, as shown inFig. 8, will cause knob I4 on the bottom end of the gear shift lever I3to engage gate I55 for moving yoke rod I45 to the position where notchI41 engages a detent I34 to shift fork I 53 to the left (looking at Fig.2), whereupon sleeve I05 will slide over the clutch member 90 untilteeth IM and I06 are meshed. The drive connection v will now be from thedriving shaft through the intermediary just previously described, plusthe clutch member 90, sleeve I05 and clutch member I03 which may beformed on ,the driven shaft.

The free wheeling unit or clutch may be omitt ed from our automatictransmission, as it will operate satisfactorily without such a unit. Theuse of a free wheeling unit as illustrated in Fig. 2, renders use ofengine-clutch entirely unnecessary except when starting the vehicle fromrest, and also eliminates any possible shock which might attend anautomatic change of gears from intermediate to high or vice versa. Inthe modification of the 'free wheeling mechanism illustrated in Fig. 3,operation of the clutch would be necessary in order to effect a manualshift from low to automatic gear position. It will be necessary,however, when shifting from low to automatic, using the free wheelingmechanism illustrated in Fig. 2, to release engine throttle control I0.temporarily in order to permit the engine to reduce its speed below thatof the driven member 46 of the overrunning clutch member.

When the car is in automatic second position, acceleration of the speedof the driven shaft 1, will, when a predetermined speed is obtained,dependent upon the strength of the spring I2I tend to cause thecentrifugal weights I23 to fly outwardly, for pivoting bell crank leversI22 about their pivots, which would causethe arms of the bell cranklevers engaging in the groove I I1 of the sleeve II5 to move the sleeveto the right against the force of the spring I 2I The shift fork I25,engageable in the groove H6 in the through the intermediary justdescribed, move the shift fork I 15 to break-the driving connectionbetween the jaw teeth on the gear 83 and jaw clutch member 90, uponrelease of torque between such teeth incident to closing of the enginethrottlethat is, break the interlocking teeth connection shown in Fig.7, and will move the clutch member 90 to the right where the jaw clutchteeth 95 will engage the corresponding teeth 91 on clutch member 98.

It will be remembered that sleeve I interlocks teeth IOI on jaw clutchmember 90 and teeth I04 on gear I03. Jaw clutch teeth 95 will notinterlock with the teeth 91 until the speeds of members90 and 98 areapproximately synchronized-'that is, until both are travelingapproximately at the same rate of speed. If the member 98 is travelingat a faster rate of speed than the jaw clutch member 90, the teeth 91will not mesh with the teeth 95, but will jump the interstices due tothe cammed surfaces 95 and 91' of the teeth. The introduction of a freewheeling or overrunning clutch mechanism between the driving shaft andthe gear 98, as shown in Fig. 2 or in modification of Fig. 3, willpermit such teeth to interlock or engage practically without any shockor clash.

When thegear ratio is changed from a second gear ratio to a high gearratio, the drive will then be direct from the driving shaft 21, throughoverrunning clutch 43, intermediate shaft 3I, clutch member 98, teeth91, meshing with teeth 95 on clutch member 90, teeth IN on clutch member90 meshing with teeth I06 on sleeve I05, which teeth I06 also mesh withthe teeth I04 on the member I03 which is formed on the driven shaft 1.It will be noted that when the transmission is in automatic position,the gate I55 is opposite the gate I66 so that when it is desired toshift from automatic high position to a manually selective second,manipulation of the gear shift lever to such position, (see Fig. 8),will cause the knob I4 to move the' pin I80 against the compression ofthe spring I82 in order to enter the gate I66. Movement of the yoke rodI60 to a point where the notch I62 engages the detent I34, will shiftfork I15 to move the jaw clutch member 90 that is, move the teeth 95 ofthe jaw clutch member90 out of engagement with the teeth 91 of the gear98 upon release of torque between such teeth incident to closing of thethrottle and move the teeth 94 into interlocking engagement with theteeth 92 on the gear 88, whereupon the driving connection will be aspreviously described, for automatic second gear ratio.

The lost motion connection between the sleeve I83 and the yoke rod I80will permit the latter to be shifted without opposition from thecentrifugal weight mechanism. When the automatic shift from intermediateto high is made, the rocker arm I90 carried by the sleeve I88 is movedto the right, looking at Fig. 4, and moves the yoke rod I60 with itbecause of the engagement of head I 92 with shoulder 20I on yoke rodI60. When the yoke rod I60 has been moved to a position where notch I6lwill engage a poppet, such as I34, the head I92 will have started downthe incline of the cutaway portion I95 on the shaft I94 to free itselffrom engagement with the shoulder 20I. The yoke rod I60 may then, ifdesired, be manually shifted to selective second gear ratio, aspreviously described, without opposition from the centrifugal weightmechanism, which will retain the sleeve and rocker arm in their righthand positipn.

A slidable bar 5I2, supported at one end in a seat 5I3 in the wall 22 ofthe transmission case and at the other end by a headed pin 5I5extending'through a bifurcated portion of the bar and secured to theside wall of the case 5, is provided with an arm 5| 4 having a fork 5I6for engaging a lower portion I4 of the shift lever I3. That end of thebar slidable within slot 5I3 is provided with a pair of notches 622 and524, the latter of which is adapted to be engaged by a spring pressedpoppet 526 received in a bore in the case and retained therein by screw528 for holding the bar against undesirable movement.

An interlock 520 is adapted to drop into notch 522 to permit movement ofshaft I94 and to be moved into engagement with notch 52I in the shaftI94 by shifting of bar 5I2 for locking shaft I94 against movement forthe purpose of looking out the automatic speed changing mechanism.

whenever a forced shift from either of the automatic positions toselective second or high is made. When the shaft I94 is locked againstmovement, the shift rod I60 will be freed from movement responsive tooperation of the centrifugal weight mechanism and will stay in theposition to which it is manually moved by the shift lever whichsimultaneously engages fork 5I6 carried by the bar 5I2 for the purposeof moving the same whenever a manual shift to selective second or highis made. The head I8I of the spring pressed pin is rounded to hold thegear shift lever in either selective second or high by camming the knobI4 into corners between the end of the gate I66 and sides of the gateI65.

If, when the transmission is in automatic high, the speed of the drivenshaft is decelerated to effect an automatic shift from high tointermediate, the centrifugal weights I23 will collapse when the speedof the driven shaft attains a predetermined rate whereupon the sleeve II5, fork I25 and sleeve I83 will be moved to the left with theassistance of spring I2I, to move the head I92 on the rocker arm toreengage shoulder 20I. The bolt I85 engaging the flatted portion I66 onthe yoke rod I60 will engage the shoulder on the yoke rod at the end ofthe flatted portion and move the yoke rod to the left to a positionwhere notch I62 will engage a poppet such as I34. Fork I15 will beshifted thereby to move clutch member 90 out of engagement with member98 and into engagement with gear 83. Before the automatic shift can beeffected, the torque between the jaw teeth 95 and 91 must be released,such as by closing of the engine throttle.

If a manual change from automatic second to selective high is desired,the knob I4 of the shift lever may be forced into gate I66 against thetension of spring pressed pin I80 for the purpose of moving yoke rod Ito the right to interlock clutch members 90 and 98 through jaw teeth 95and 91. Since the shoulder on the yoke rod I60 formed by the fiattedportion I now abuts the end of bolt I85, the yoke rod must be manuallyshifted against the compression of spring I2I to get selective high, butthe shift will be assisted by tendency of the centrifugal weights tomove outwardly.

The springs I61 and I68 are adapted to take up the movement of theclutch member 90 caused by the jumping, of the jaw teeth during manualshifting and before the interlocking of the teeth. These springsposition the gate I66 on the yoke rod I60 so as to be capable of lateralmovement with respect thereto.

The relative positions of the selective high and to conform to presentstandard shifts wherein second speed position is at the upper right handcorner and high speed position is at the lower right hand position, bythe use of suitable mechanism to reverse the action of the shift lever,such as by using a bell crank lever to coop rate with the end of theshift lever to reverse Eire movement thereof.

Referring to Figs. 9 to '12, which illustrate a modified form of themechanism for automatically operating the'shifting mechanism, there isshown a valve mechanism for. controlling the application of vacuum to apiston which actuates the shifting mechanism. Referring to Fig. 9, thereis shown a transmission case having a housing 6 for encasing thespeedometer mechanism, which housing may be secured to the rear end ofthe transm ssion case in any suitable manner such as by bolts 250. Thespeedometer housing 6 is provided with an enlargement for accommodatingthe mechanism for controlling the operation of the vacuum valve. A coverplate 252 is secured to the housing as by bolts 254. In thismodification the internal construction of the transmission is'identicalwith that shown in Fig. l

2 with the exception of that part of the yoke rod mechanism illustrated'in Fig. 10, and with the further exception that the vacuum controlledapparatus is substituted in place of the centrifugal weight mechanism.

Speedometer gear 1| is amxed to the driven shaft 1 as by a key 256 andmeshes with a worm 12 on the speedometer shaft 13. A bushing 258 .isthreaded into the housing 6 to provide a bearing surface for thespeedometer drive shaft 13. The end of the speedometer drive shaft isreduced at 260 and journaled in the cover plate 252. The shaft 13 issplined intermediate the reduced portion 260 and the worm 12. A collar262 having a plurality of arms 264 is splined on the.

shaft 13. Bell crank levers 266 are pivoted as at 268 to the arms 264'and are provided with weights 2 which are adapted under the influence ofcentrifugal force to 'fly radially outwardly. A hub 212, having a groove214 and a drum-shaped shell 216, is slidably splined on the shaft 13intermediate the reduced portion and the collar 262. One arm of each of,the bellcrank levers 266 is adapted to bear against the end surface ofthe drum 216 for the purpose of moving the same to the left when thecentrifugal weights fly outwardly.

The cover plate 252 is provided with a passageway 218. A conduit 280connected to a source of vacuum such as the intake manifold of aninternal combustion engine, is connected by means of a suitable coupling282 to one end of the passageway 218. A conduit 284 is connected to theother end of the passageway 218 and leads to one end of a vacuumcylinder 286. A valve member 290 disposed in a bore 292, intercepts thepassageway 218 and is biased by a spring 284 to the right (looking atFig. 11). The valve member is provided with an am 298 for engaging inthe groove 214 of the collar 212 so as to be moved thereby. A port 300is provided in the valve member 290 for interconnecting the differentportions of the passageway 218 to provide communication between theconduit 280 and the conduit 284. A second port 30! is provided in thevalve member 290 for placing the vacuum cylinder in communication withatmosphere through conduit 284,

plate. A plug 302 threadedly engages an-enlarge ment in the bore 292 forholding the spring 284 in position.

306. A shaft I84, rigidly affixed to the wall 22 10 of the case, has asleeve 3l8 slidably secured thereupon, which is provided with a slot 320adapted to receive one end of the lever 315. The sleeve is provided witha pair of arms 322 to carry a pin 324 on which is pivotally mounted alever 15 326 having a. diamond-shaped head 328 which is adapted undercertain circumstances to engage in notch 330 in the yoke rod I60 ornotch 332 in the shaft I94.

A lug 329 is provided on the yoke rod I60 for engagement with one of thearms 322 whereby the yoke rod may be moved in one direction. Thismodification of the invention willaccomplish the same results as areaccomplished with the centrifugal weight mechanism shown in Fig. 2, but

the mode of operation is slightly different. 'Assuming the transmissionto be in automatic second gear ratio, the driven shaft 1 will be drivingthe speedometer gear 1| which in turn meshes with the worm gear 12 onthe shaft 13. When the speed of the driven shaft 1 attains apredetermined rate, the centrifugal weights 210 will tend toflyoutwardy, causing the other-ends of the bell crank levers 266 topress against the drum 216, thereby moving the same to the left,(looking at Fig. 11).

Since the valve 280 is connected with the hub 212, port 300 will bemoved into a position between the portions of the pas-- .sageway 218'to. provide communication between conduit 280 and conduit 284 and toclose vacuum 40 cylinder 286 to the atmosphere; The conduit 280 leads toa source of vacuum, which will cause the piston (not shown) in thevacuum cylinder 286, as soon as communication is established with theend of the vacuum cylinder 286, to be moved to the left, (looking atFig.9). This will cause the arm 308 to move the lever 315 to the right,which 1 will tend to slide the sleeve 3l8on the shaft I94 Since the head328 of the lever 326 is connected to thearm and, as shown, is held inengagement with the notch 330 on the shaft I60, the yoke rod 160 will bemoved to the right, when the piston in the vacuum cylinder is put incommunication with a source of vacuum to effect an automatic-shift fromsecond to high. Notch 332 is head 328 provided inthe shaft I84 forreceivin to permit the yoke rod I to be shift (1 back to manualselective second position, without opposing the effect of vacuum on thep ston in the vacuum cylinder 286,. The piston (not shown) in 9 thevacuumcylinder 286 will be held in its retracted position as long as thevalve 290 is held open to permit the applicatLon-of suction to the faceof the piston. As soon as the valve member 290 moves to close the sourceof vacuum to the face of the piston and opens the same to theatmosphere, a spring in the vacuum cylinder will move the piston tochange the gear ratio by an automatic shift from'high tosecond gearratio.

To that end, the arm 322 on the sleeve 3| 8 will .70 then engage thelug320 onthe shaft I60 forf moving the same to the left, whicht will shiftclutch member 90 out of engagement with member 98 and into engagementwith gear 83. If the transmission is in automatic second position and amanual shift to selective high is made, the knob 14 on the end of theshift lever will enter gate i66 and move yoke rod 166 to the right, theknob being held in selective high position by the camming effect of therounded head 181 of the pin biasing the knob into a corner between theside of the gate 155 and end of gate 166. Movement of the yoke rod 166to the right will carry sleeve 316 and lever 326 with it. The force ofthe spring in the vacuum cylinder will be insuflicient to move the yokerod 166 back to second speed when the lever is positioned in selectivehigh.

Referring to the modification shown in Figs. 13 and 14, there isillustrated a two-speed transmission having areverse gear, an automaticshift from low to high gear, using a jaw tooth clutch umember, and anoverrunning clutch in high gear.

A transmission case 356 is provided with a. series of walls351, 352 and353 which provide support for the yoke rod and shaft bearings. shaft 355is journaled in a bearing 356 supported by the wall 351 and retainedtherein by snap rings 358. A driven shaft 366 is journaled in a bearing362 supported by.the wall 352 and retained therein by a snap ring 363and plate 364. A reduced front end portion of the driven shaft 366 isjournaled in roller bearings 366 in the "counterbored end of the drivingshaft 355. A

countershaft 368 which carries a cluster of gears is journaled at itsopposite end in the walls 351 and 352 of the casing. The end of thedriving shaft 355 is formed to provide a helical gear 316 which isadapted to ,be in constant mesh with a helical gear 311 on thecountershaft 368. A shell 312 forming the driving part of an overrunningclutch mechanism is splined andkeyed to the driving shaft 355.

A driven member 314 of the overrunning clutch mechanism is fitted to abushing 316 which in turn is fitted to driven shaft 366 and adapted torotate therewith. The driven member 314 of the overrunning clutch isprovided with a series of cammed faces radially spaced about itsperiphery. For each of the cammed faces (not shown) thereiis provided aroller 318 which is adapted to roll upon the cammed surface and upon theinner surface of the drum 312. The operation of this overrunning clutchmember and the construction is-identical with that illustrated in Figs.2 and 3 of the drawings. Thrust washers 319 are provided within the drum312 for the purpose of retaining the rollers 318 in position. A snapring 366 is secured adjacent the outer end of the drum 312 for thepurpose of confining one of the washers 319 imposition. V

The driven member 314 of the overrunning clutch mechanism is providedwith a series of jaw teeth 382, the faces of which are tapered orpitched. A clutch member 385 slidably splined on the driven shaft 366 isprovided on both of its faces with a series of tapered jaw teeth 386 and381. The jaw teeth 386 are adapted to interlock with the teeth 382 onthe driven member 314 of the overrunning clutch. Jaw teeth 381 on theclutch member 385 are tapered similarly to the teeth 382 and are adaptedto interlock A driving member 385.

and the driven shaft is at rest, by breaking the driving connectionbetween the engine and the transmission such as by operating a clutch,which will have the effect of stopping the rotation of gear 396 so thatclutch member 385 carried on the driven shaft may be moved into engage-'ment therewith. As long as gear 396 rotates faster than clutch member385, the teeth cannot interlock because the pitched faces thereof willtend to push clutch member 385 away from gear 396 and cause the teeth tojump the interstices between the teeth on the cooperating member.

Similarly, jaw teeth 382 on member 314 will not engage teeth 386 on thejaw clutch member whenever member 314 is rotating faster than Theoperation of the jaw teeth illustrated in this modification of theinvention is identical with that of the jaw teeth illustrated in Figs. 2and 1..

The helical gear 396 is in constant mesh with a gear 393 which is one ofthe gears on the countershaft 368. Because of the constant intermeshingof the gears 316, 311, the gear 393 is adapted to drive the helical gear396 upon the driven shaft, 366. The countershaft carries a third gear396 which is in constant mesh with an idler gear 391 carried upon ashaft (not shown), and theidler gear 391 is in constant mesh with a'gear466 freely rotatable on the driven shaft 366. The driven shaft 360carries a thrust washer 461 between the gear 466 and the bearing 361.The gear 466 is provided with a set of internal teeth 462 which areadapted to mesh with teeth 463 carried by a hub 464 which is slidablysplined to the driven shaft 366 and which is provided with an annulargroove 465 which is adapted to receive a fork 461 carried by yoke rod436.

The gear 466 is adapted to rotate with the driving shaft 355, since itis connected thereto through a series of gears 391, 396, 311 and 316.When the hub 464 is moved to the right (looking at Fig. 13),intermeshing of teeth 462 and 463 is adapted to lock the gear 466 to thedriven shaft 366 to provide reverse gear.

The driven shaft 366 has fixedly secured thereto a hub 412 retained inposition by snap rings 413, which hub carries a series of arms 415similar in construction to the arms 126 shown in Fig. 2. Pivoted to eachof the arms 415 by pivot pin 416 is a bell crank lever 411 having oneend 418 provided with a weight and the other end 416 adapted to engagein a groove 426 in a sleeve 422 which is slidably positioned on thedriven shaft 366. The sleeve 422 is provided with a second annulargroove .424 which is adapted to receive a shifting fork 426, and isbiased to the right by a compression spring 428 which is disposedbetween one face of the sleeve 422 and the hub 412.

The weights 418 are adapted to be moved radially outwardly under theaction of centrifugal force to pivot the bell crank levers 411 on theirpivots 416 for the purpose of moving the sleeve 422 to the left, lookingat Fig. 13.

Slidably secured in the walls 351, 352 of the transmission casing 356are a pair of yoke rods 436 and 431 which carry the forks 394 and 461for shifting the members 385 and 464, respec- 'lease of torque betweentively. The yoke rod 430 carries at one thereof a collar 432, which maybe secured by a bolt 434, and which carries the shifting fork 401. Acollar 435 secured by a bolt 436 to the end yoke rod 430 is providedwith a gate 431 which poppet 460, whereby the teeth 403 on the hub willhave engaged the teeth 402 on the gear 404, so that the driven shaft 360will be in reverse gear ratiowith respect to the driving shaft 355.

The yoke rod 43! carries a sleeve or gate 440 held in position thereonby spring 444 and pin 446. A collar 441, carrying the shift fork 394, issecured to the shaft by a bolt 448 and engages one end of the spring444. The yoke rod 43! also carries adjacent one end thereof a sleeve450secured thereto by a bolt 455 which carries the fork 426 for engaging inthe groove 424 in the sleeve 422. A predetermined speed of rotation ofthe driven shaft 360 will cause the weights 4!8 carried by the hub M2 tofly radially outwardly upon rethe interlocking jaw teeth incident toclosing of the engine throttle, thereby causing the lever 4!1' whichengages groove 420 on the sleeve 422 to move the same to the left,looking at Fig. 14. Movement of the sleeve 422 to the left, will, byvirtue of the fact that shift fork 426 engages groove 424 on the collar422, move the sleeve 450 and the yoke rod 43! to the left, to a.position where notch 458 engages a poppet such as 460. This leftwardmovement of the yoke rod 43! which carries collar 441, will cause shiftfork 394 to move the clutch member 385 to the left, thereby moving jawteeth 385 out of engagement with jaw teeth 388 and moving jaw teeth 386into interlockingengagement with jaw teeth 382 on the driven member 314of the overrunning clutch mechanism. It will be understood, of course,that before this action takes place, manipulation of the shift leverwill have moved the clutch member 385 for moving the teeth 381 intoengagement with the jaw teeth 388 on the gear 390, which will give thelow gear driving connection.

A boss 452 is carried by the side wall of the transmission casing forthe purpose of holding the gear shift lever in automatic position whenthe automatic shift from low to high takes place. The sleeve-440provides a gate for the reception of the knob 439 carried by the gearshift lever. The sleeve gate 440 is provided with an offset portion 454for the purpose of permitting the knob 439 to'be locked in behind theboss 452 and against the tension of spring 444. This may be accomplishedafter the transmission is placed in automatic by moving the handle ofthe shift lever to the right.

After the car is sufliciently accelerated in low gear, the driven shaft360 will attain a speed suf ficient to cause the centrifugal weights M8to fly radially outwardly, causing the operation just described,'forplacing the transmission in high gear ratio.

In the modification illustrated in Fig. 13, it will be necessary inorder to permit the automatic shift from low to high to take place thatthe throttle governing the speed of the engine be temporarily releasedin order to relieve the pressure or torque between the interlockingteeth 38! and 388, so that these teeth may be disengaged after theactuation of the centrifugal weight mechanism.

When the driven shaft 360 has been decelerated to or beyond apredetermined rate of speed, the centrifugal weights will tend tocollapse, and, if the power is temporarily reduced at such time torelieve the pressure or torque between the interlocking teeth 382 and386, the" sleeve 422 under the influence of the spring 428 ,will. help,with the assistance of spring 444, to

move the shifting fork 426 to the right, for the purpose of shifting theclutch member 385 out of engagement with member 314 and into engagementwith the jaw teeth on the low gear 390- to effect an automatic shiftfrom high to low gear.

The action of the centrifugal weight mechanism shown in Fig. 14 ispractically identical with that shown in Fig. 4 except that in Fig. 14

.the centrifugal weight mechanism is in a position reverse to that shownin Fig. 4. Because .the transmission illustrated in Figs. 13 and 14 isonly two speed forward and one reverse, for that reason there is onlyone forward gear shift posithe vehicle momentarily releases the throttlegovermng the engine speed. .The overrunning clutch mechanism practicallyeliminates any possibility of a shock when the jaw teeth interlock uponan automatic shifting into high, but it may be omitted without affectingthe efliciency of the speed changing mechanism, if desired.

A manual control for obtaining a manual forced shift from automatic highto second may be provided similar to that disclosed in Figs. 2 to 7, ifdesired.

Fig. 15 illustrates a modified form of a clutch mechanism which may beused in place of the clutch mechanism illustrated in Fig. 13 and whichmay readily be adapted for use in the transmission illustrated in Fig.2. In the clutch mechanism illustrated in Figs. 2 and 13, the shiftableclutch member must first be disconnected from one of the clutch elementsbefore it is shifted into engagement with the other of the clutchelements. The shiftable clutch member of the clutch mechanism shown inFig. 15 is connected through an overrunning clutch with the second speedgear and is adapted to be shifted to engagement with the high speedclutching element without being disconnected from the second speeddriving gear.

The driven shaft 360' thereon, but adapted to rotate with respectthereto, a helical gear 390 in constant mesh witha helical gear on thecounter-shaft such as gear 393. The helical gear 390 is provided with ahub 500 which carries a set ofexternal radial teeth 502. A drivingmember 503 of an overrunning clutch mechanism is provided with aninternal set of teeth 504 which are adapted to mesh with and slide overthe teeth 502 on the hub 500. A series of rollers 505 are disposedbetween an inner annular surface of the driven member 385' of theoverrunning clutch mechanism and external has suitably secured radiallydisposed cammed surfaces provided on the driving member 503. This clutchis adapted to provide a one-way drive between the helical gear 390' andthe driven member 385 so that the driven member 385 will always rotateas fast as the helical gear 390', but will be free to overrun thesame.

An annular groove 392' is provided on the.

driven member of the overrunning clutch mechanism for receiving ashifting fork carried by the yoke rod for the purpose of shifting orsliding the member 385. The driven member 385 of the overrunning clutchmechanism is provided with an internal set of teeth 501 which areadapted to slide upon the driven shaft 360" and to mesh with the teethor'splines 5l0 carried thereby. A helical gear 310 is connected to orformed on the end of the driving shaft and is provided with an annularring member 314 having a series of pitched surfaced jaw teeth laterallydisposed around the face thereof. The driven member 385' of theoverrunning clutch mechanism is provided with a series of pitched facedjaw teeth 386 which are adapted under certain circumstances to mesh withthe jaw teeth 382' carried-by the member 314' to provide a directdriving connection between the driving and the driven shafts.

The slidable member 385' of the clutch mechanism is shown in automaticsecond position, so

that the drive between the shafts will be from helical gear 310' throughthe gears on the countershaft, helical gear 390, hub 500, driving member503, and driven member 305', the teeth 501 of which are in mesh with thesplines 5l0 on the driven shaft 350.

The member 385' is adapted to be shifted to the right, looking at Fig.15, to shift teeth 501 out of engagement with the splines 510 for thepurpose of breaking the driving connection between the helical gear 390'and the driven shaft 360 v and to permit the transmission to be placedin reverse gear ratio.

The surfaces of the jaw teeth 302', 386' are pitched so that the teeth382' are adapted to overrun or ratchet over the teeth 386 until thespeed of rotation of the member 314' falls below or is approximatelysynchronized with that of the member 385. This is necessary to preventthe teeth on the driving member 314' from picking up the driven member385' when the driving member is rotating at a greater rate of. speedthan the driven member, to prevent the possible breaking of parts of thetransmission. When the speed of rotation of the driven member 385' keyedto the driven shaft 360' attains a predetermined or critical rate, theautomatic gear changing mechanism, such as that shown in Fig. 13, isadapted to-shift or slide the member 385' for meshing the teeth 382' and386'. This action-that is, the automatic shifting from low to high, willnot take place until the torque between the intermeshing teeth isreleased, such as byclosing of the engine throttle, approximately tosynchronize the speed of rotation of the driving member 314 with that ofthe driven member When the jaw teeth S82 and 386' engage, the teeth willdrop into the interstices between the jaw teeth and the engaging member.The driving connection will then be from the driving shaft throughmember 314, interlocking teeth 32:2 and 386', and driven member 385, theteeth 501 of which are meshed with the splines 5l0 of the driven shaft360.

When the car is in automatic high, the driven member 385' will berotating at a greater rate of speed than the driving member 503 of theoverrunning clutch, and for that reason, will overrun the secondspeedgear 390, When the speed of the driven shaft 360' has been deceleratedto that point where the automatic speed changing mechanism will beoperable to effect an automatic shift from high to second gear, thedriven member 385 will, upon release of torque between jaw teeth 382'and 386, be shifted out of engagement to break the high gear drivingconnection and to permit the helical gear 390 to drive the driven member385' through the overrunning clutch, as previously described.

While several specific embodiments of our invention have beenillustrated and described, it must be appreciated that manymodifications may be made in the construction thereof without departingfrom the scope of the invention, and for that reason we do not desire tobe limited to any particular form or arrangement except in so far assuch limitations are included in the following claims.

We claim:

1. An automatic transmisison comprising a driving shaft, a driven shaft,change speed gearing adapted to interconnect said shafts in a pluralityof different driving ratios, jaw clutch mechanism having pitched axialteeth surfaces operable only whenever approximate synchronizationbetween the rotative speed of said teeth occurs for connecting saidchange speed gearing to said driven shaft in a plurality of diiferentratios, means operable responsive to a predetermined speed of rotationof the driven shaft for 'actuating said clutch mechanism to effect anshaft and mounted for rotation therewith, said clutch mechanism beingadapted to interconnect said members on the driving and driven shaftsfor driving the driven shaft in synchronism with the driving shaft, ashift fork for actuating said clutch mechanism, means operable at anytime after a predetermined speed of rotation of the driven shaft hasbeen attained for automatically shifting said fork, and a manipulativeshift lever for shifting said forkfor changing the gear ratio withoutregard to the speed of the driving or driven shafts.

3. In an automatically variable change speed mechanism, a driving shaft,a driven shaft, gearing adapted for interconnecting said shafts in aplurality of different speed ratios, a clutch mechanism operable foreffecting different relationships between said gearing and said shaftsto provide a plurality of driving speed ratios between the driving shaftand the driven shaft. means operable at any time after a predeterminedspeed of rotation of the driven shaft has been attained forautomatically actuating said clutch mechanism to provide a normal speedratio between the driving shaft and the driven shaft, and manipulativemeans operable without opposing said means for operating said clutchmechanismto select a speed ratio between the driving and driven shafts,other than a normal one.

4. An automatically variable change speed mechanism comprising a drivingshaft, a driven shaft, gearing for interconnecting said shafts in aplurality of different speed ratios, a clutch mechanism for selectingthe driving speed ratios between the shafts, a shifting fork foroperating said clutch mechanism and carried by a yoke rod, meansoperable at any time after a predetermined speed of rotationof thedriven shaft has been attained for automatically moving said yoke rod toselect a normal driving speed ratio with regard to the speed of thedriven shaft, a manipulative lever for moving said yoke rod to select adriving speed ratio without regard to the speed of the driven shaft, anda lost motion connection between v said yoke rod and said means topermit the operation of said manipulative lever without opposition fromsaid means.

' 5. An automatic transmission having in combination a driving shaft, adriven shaft, a train of gears operatively connected with one of saidshafts, a clutching element for each of said shafts and mounted torotate therewith, a clutch member cooperable with said train of gearsand said clutching elements for providing a plurality of driving speedratios between thedriving and driven shafts, means operable at any timeafter a predetermined speed of rotation of the driven' shaft has beenattained for automatically actuating said clutch member to provide achange in the driving speed ratio between the driving and the drivenshafts, said clutch member being operable only'upon a temporaryreduction of the speed of rotation of the driving shaft relative to thatof the driven shaft.

6. An automatically variable change speed mechanism comprising a drivingand a driven shaft, a change speed gearing, and a clutch forinterconnecting said shafts in a plurality of different, speed ratios, ayoke rod carrying a shifting fork for operating said clutch, meansoperable by the driven shaft atany selected time after the speed ofrotation thereof attains a predetermined rate and connected through alost motion connection with said yoke rod for operating said clutch toeffect an automatic change in the speed ratio between said shafts, andmanipulative means connectible to said yoke rod for actuating saidclutch to change the speed ratio between said shafts without regard tothe speed of the driven shaft.

7. An automatically variable change speed mechanism comprising a drivingand a driven shaft, means for interconnecting said shafts through achange speed gearing in a plurality of different gear ratios including aclutch for selecting the different gear ratios, means operable by thedriven shaft at any selected time after the speed of rotation thereofattains a predetermined rate for automatically actuating said clutch toselect a normal driving gear ratio between the driving and drivenshafts, and whenever the torque between said shafts is released incidentto a reduction of the difference between the speeds of rotation of saidshafts, a lostmotion connection between said clutch and said means forautomatically actuating said clutch, and manipulative means connectiblewith said clutch and operable for changing the gear ratio between thedriving and driven shafts without regard to the speed of rotation ofsaiddriven shaft.

8. An automatic transmission having in combination a driving and adriven shaft, gearing for interconnecting said shafts in a plurality ofdriv ing speed ratios and including a clutch operable for selecting thevarious driving speed ratios, a yoke rod carrying a shift fork forcontrolling said clutch, means controlled by the speed of rotation ofthe driven shaft for automatically actuating said yoke rod and shiftfork, a lost motion con nection betweensaid means and said yoke rodwhereby said yoke rod may be moved independently of said means, and ashift lever connectible to said yoke rod for manually moving the sameindependently of said means.

9. In a device of the class described, a driving shaft, a driven shaft,a jaw tooth clutch member connected to one of said shafts, a pluralityof clutching elements, one of which is provided with jaw teeth,connected to the other of said shafts and adapted for driving engagementwith said clutch member for interconnecting said shafts in a pluralityof driving speed ratios, an overrunning clutch mechanism adapted to bedisposed in one of the driving connections between said shafts, andmeans operable at any time after the driven shaft has attained apredetermined speed of rotation and upon a temporary reduction of thespeed of rotation of the driving shaft for automatically shifting saidclutch member into engagement with said jaw tooth clutching element forchanging the driving speed ratio between said shafts.

10. Automatically variable change speed mechanism comprising incombination a driving shaft, a driven shaft having a member connectedthereto to be rotated therewith, means driven bysaid driving shaft andconnectible to said member,

a clutch mechanism for interconnecting said means and said member forinitiating the rotation of said driven shaft in an initial speed ratio,a member fixed to said driving shaft, said clutch mechanism beingadapted to interconnect said member on said driving and driven shaftsfor driving said driven shaft at an increased speed ratio, centrifugalforce actuated means responsive to the rotation of said driven shaft andoperable at any speed thereof above a predetermined rate for shiftingsaid clutch mechanism to interconnect said members, and a manipulativelever operable for shifting said clutch mechanism out of engagement withsaid driving shaft member and into operative relationship with saidmeans to effect a selective change to an initial driving speed ratio.

11. In an automatically variable change speed mechanism, the combinationof adriving shaft with a driven shaft, means including an overrunningclutch. having members connected to each of said shafts, respectively,affording a onesaid driven shaft upon disconnection .of. said clutchelement, and manipulative means for effecting a selective drivingconnection between said shafts and for rendering said centrifugal forceresponsive means ineffective.

CARL F. RAUEN. AND E.

